1. Field of the Invention
The invention relates to graphical display, in particular to anti-aliasing for graphical display.
2. Description of Related Art
In graphical user interfaces, shapes are typically displayed as a combination of pixels. Shapes may include text or graphics. A pixel is typically a portion of a display that has a hue, saturation, and luminance value at any particular point in time. Images of text or graphics are created as combinations of pixels throughout the display. A shape to be displayed may in some cases only imperfectly be rendered as a combination of pixels. For example, where a mathematical representation of the shape has a curved edge, pixels in the set of pixels used to render the shape may have edges that do not exactly correspond to the edge of the shape. Thus, in such an example, an imperfect rendering of the mathematical shape occurs. In particular, as characters of text are displayed on a display in a size that is small relative to the size of pixels, imperfections may occur.
One attempt to correct for such imperfections is a technique known as anti-aliasing. Under some anti-aliasing techniques, intensity of a pixel may be adjusted where an edge of the corresponding shape does not correspond to an edge of a pixel. U.S. Pat. No. 5,390,289, entitled “Anti-Alias Font Generation,” which is incorporated herein by reference, describes one technique of anti-aliasing for font generation.